A biguanido bactericide or N-alkyldiaminoethylglycine (hereinafter generally referred to as bactericide) is effective for inhibition of the formation of dental plaque and has hitherto been added to dentifrices. On the other hand, in general, a foaming agent (surfactant) and a binder to be added to dentifrices are anionic ingredients. Then, the bactericide reacts with these ingredients to form a complex, which results in remarkable loss of bactericidal activities of the bactericide added. Therefore, there is a problem that, even when bactericide is added in order to inhibit the formation of dental plaque, in practice, its effect can scarcely be expected.
For solving such a problem, a composition employing a nonionic surfactant as a foaming agent is disclosed in U.S. Pat. Nos. 4,080,441, 4,110,429 and 4,118,476 as well as British Patent No. 1,573,356. However, there is another problem that, although such a composition maintains bactericidal activities, its foaming properties and feeling for use are deteriorated.